Conventional bus bars of a power conversion device are configured such that a narrowed area is formed near a terminal of each of the positive-side bus bar and the negative-side bus bar, and the narrowed areas are formed in such a positional relationship as to coincide with each other in the opposition direction of the positive-side and negative-side bus bars opposed to each other in the up-down direction (see, for example, Patent Document 1). Owing to such a structure, positive and negative currents coincide with each other in the up-down direction at the narrowed areas and the inductance is reduced, whereby surge voltage can be reduced.
However, since the inductance is reduced, on the other hand, short-circuit current increases, thus causing a problem that an electromagnetic force of the bus bars increases.